[unreadable] Using data from a study of the sexual networks of African American urban adolescents in San Francisco, CA, and from the US Census, this application will be one of the first to assess how individual factors, network characteristics, and neighborhood socioeconomic context combine to create HIV and STI risk. It is particularly important to understand why minority adolescents living in resource-poor communities are vulnerable to STIs in the light of the inability of individual-level factors to fully explain disease risk in this population. This study aims 1) to identify sexual networks features that are associated with individual-level STI risk, controlling for individual-level demographic and behavioral risk factors, 2) to identify neighborhood level socioeconomic characteristics that are associated with individual-level STI risk, and 3) to determine if network- and individual-level characteristics mediate the relationship between neighborhood-level socioeconomic context and individual-level disease risk. Identification of risk factors at the individual, network and community levels will provide the targets necessary for the development of the next generation of multilevel interventions to prevent HIV and other STIs in disadvantaged communities. [unreadable] [unreadable] [unreadable] [unreadable]